Methods for reduction of volatile organic compounds (VOCs) content in air depend on the application considered. For low concentration and low flux, nonthermal plasma methods are often considered as efficient. However, the complex chemistry involved is still not well understood because there is a lack of data sets of byproducts formation. To overcome this issue, rapid analytical methods are needed. We present the coupling of a rapid chemical ionization mass spectrometer (CIMS) for the real-time analysis of the VOCs formed during a degradation experiment. The high-resolution instrument used allows for chemical ionization and direct quantification of nontargeted compounds. This method is successfully applied to degradation experiments of acetone in a phototriggered nitrogen plasma discharge. Two regimes were highlighted: efficient conversion at low concentrations (<100 ppm) and moderate efficiency conversion at higher concentrations (>100 ppm). Those two regimes were clearly delimited as the sum of two exponential curves occurring at respectively low and high concentrations. Many byproducts were detected; in particular, HCN presented a significantly high yield. Nitrile compounds (acetonitrile, propionitrile, ...) are formed as well. To a lower extent, ketene, acetaldehyde, and formaldehyde are observed. The association of the high-resolution mass spectrometer to the plasma reactor will allow further insights into the plasma chemistry and comparison to modelization.

中文翻译：

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使用紧凑型FT-ICR MS在等离子体反应器中进行直接和实时分析：氮中丙酮的降解和副产物的形成。

减少空气中挥发性有机化合物（VOC）含量的方法取决于所考虑的应用。对于低浓度和低通量，非热等离子体方法通常被认为是有效的。然而，由于缺乏副产物形成的数据集，因此所涉及的复杂化学方法仍未被很好地理解。为了克服这个问题，需要快速的分析方法。我们提出了快速化学电离质谱仪（CIMS）的耦合，用于对降解实验过程中形成的VOC进行实时分析。所使用的高分辨率仪器可用于化学电离和直接定量非目标化合物。该方法已成功应用于光触发氮等离子体放电中丙酮的降解实验。强调了两种制度：低浓度（<100 ppm）时有效转换，较高浓度（> 100 ppm）时中等转换。明确地将这两种方式定义为分别在低浓度和高浓度下出现的两条指数曲线的总和。检测到许多副产物。特别是HCN的收率很高。也会形成腈化合物（乙腈，丙腈等）。在较低程度上，观察到了乙烯酮，乙醛和甲醛。高分辨率质谱仪与等离子反应器的结合将使人们对等离子化学以及与模型化的比较有更深入的了解。明确地将这两种方式定义为分别在低浓度和高浓度下出现的两条指数曲线的总和。检测到许多副产物。特别是HCN的收率很高。也会形成腈化合物（乙腈，丙腈等）。在较低程度上，观察到了乙烯酮，乙醛和甲醛。高分辨率质谱仪与等离子反应器的结合将使人们对等离子化学以及与模型化的比较有更深入的了解。明确地将这两种方式定义为分别在低浓度和高浓度下出现的两条指数曲线的总和。检测到许多副产物。特别是HCN的收率很高。也会形成腈化合物（乙腈，丙腈等）。在较低程度上，观察到了乙烯酮，乙醛和甲醛。高分辨率质谱仪与等离子反应器的结合将使人们对等离子化学以及与模型化的比较有更深入的了解。